1. Field of the Invention
This invention relates to grease purgeable bushing seals and in particular to a narrow grease purgeable bushing seal that can be installed in the same housing bore diameter as used by the bushing.
2. Description of the Prior Art
In the past it has been general practice, when sealing a bushing having a narrow cross-sectional thickness (i.e. 0.100 inch), that the outside diameter of the seal had to be larger than the outside diameter of the bushing housing. This practice had the two disadvantages of requiring a machining operation of counter-boring the housing bore for the larger outside diameter seal, and also of reducing the strength of the housing at the location of the counter bore. Prior art seals that would fit within the same housing diameter as the bushing were not grease purgeable but would "pop out" under pressure of the grease.
It is a primary object of the present invention to provide a narrow cross-section grease purgeable bushing seal which has the same outside diameter dimension as that of the bushing so that the counter-boring machining operation can be eliminated.